[Java] Refine tests and fix single-process mode (#4265)

java/test.sh

@@ -2,36 +2,25 @@
 
 # Cause the script to exit if a single command fails.
 set -e
-
 # Show explicitly which commands are currently running.
 set -x
 
 ROOT_DIR=$(cd "$(dirname "${BASH_SOURCE:-$0}")"; pwd)
-$ROOT_DIR/../build.sh -l java
 
 pushd $ROOT_DIR/../java
+echo "Compiling Java code."
 mvn clean install -Dmaven.test.skip
-check_style=$(mvn checkstyle:check)
-echo "${check_style}"
-[[ ${check_style} =~ "BUILD FAILURE" ]] && exit 1
 
-# test raylet
-mvn test | tee mvn_test
-if [ `grep -c "BUILD FAILURE" mvn_test` -eq '0' ]; then
-    rm mvn_test
-    echo "Tests passed under CLUSTER mode!"
-else
-    rm mvn_test
-    exit 1
-fi
-# test raylet under SINGLE_PROCESS mode
-mvn test -Dray.run-mode=SINGLE_PROCESS | tee dev_mvn_test
-if [ `grep -c "BUILD FAILURE" dev_mvn_test` -eq '0' ]; then
-    rm dev_mvn_test
-    echo "Tests passed under SINGLE_PROCESS mode!"
-else
-    rm dev_mvn_test
-    exit 1
-fi
+echo "Checking code format."
+mvn checkstyle:check
+
+echo "Running tests under cluster mode."
+ENABLE_MULTI_LANGUAGE_TESTS=1 mvn test
+
+echo "Running tests under single-process mode."
+mvn test -Dray.run-mode=SINGLE_PROCESS
+
+set +x
+set +e
 
 popd